Born in Milan in 1839, died in Stresa in 1895. He studied at the Brera Academy, a pupil of Hayez and Casnedi. His painting, noble in form and rich in the harmonious balance of masses and colors, excelled more in the portrait than in the genre and historical subject and managed to reach a depth of investigation hardly obtained from the Impressionist school to which he it also belonged. He exhibited in Parma, in 1870, The artist; in Milan, in 1872, Painter and Love and Freedom; in Turin, in 1880, Attraction; in Milan, in 1881, Ragione di Stato, a historical painting on the subject of the divorce of Napoleon and which is perhaps the most representative work of the artist's talents. Some interiors of the Stanga palace in Cremona and various studies for the Ragione di Stato painting are located in the Galleria d'Arte Moderna in Milan. He painted several portraits, including that of his mother and wife, also in the Galleria d'Arte Moderna in Milan. Another Portrait of the mother is owned by Dr. P. A. Ravasio. Don Antonio Venini of Milan, who was a friend and pupil of Didioni, in addition to preserving Desdemona and Otello and Boccaccio's From the novels (sketch), holds a large number of studies and drawings as well as the portraits of Venini's parents; particularly beautiful that of N. H. Giovanni Venini, executed in 1882. "The exhibition of Didioni", wrote Carlo Bozzi, on the occasion of a retrospective exhibition of the artist's works, "gives us the measure of his high value as a portraitist, which culminates in the two such lively, unforgettable portraits of the smiling old mother. In the other works he sometimes recalls Bouvier, sometimes Roberto Fontana, albeit with the background of a personal sensitivity and kindness ». "Here is also the great painting (Desdemona and Otello) left unfinished due to the artist's death and which proves how he had set about, albeit with great fervor, a work that came out of his temper ..... "An artist who is not sincere and less honest would have given completion to painting in some way".